A richacl consists of an NFSv4 acl and an owner, group, and other mask.These three masks correspond to the owner, group, and other filepermission bits, but they contain NFSv4 permissions instead of POSIXpermissions.

Each entry in the NFSv4 acl applies to the file owner (OWNER@), theowning group (GROUP@), literally everyone (EVERYONE@), or to a specificuid or gid.

As in the standard POSIX file permission model, each process is theowner, group, or other file class. A richacl grants a requested accessonly if the NFSv4 acl in the richacl grants the access (according to theNFSv4 permission check algorithm), and the file mask that applies to theprocess includes the requested permissions.